Effects of different variants of the FASN gene on production performance and milk fatty acid composition in Holstein × Simmental dairy cows

Abstract

Crossbreeding of Holstein cattle with bulls of other breeds has garnered increasing interest with respect to efforts to improve performance traits and to decrease problems with fertility and health. Therefore, the objective of this study was to compare the effects of the fatty acid synthase (FASN) gene on milk production traits and fatty acid composition of Simmental and first-generation Holstein × Simmental crossbred cows. A total of 105 cows (72 Simmental and 33 crossbred Holstein) were genotyped using the PCR-RFLP method and their fatty acid profiles were analysed. The crossbred Holstein cows with diplotype TW/AR had significantly higher fat content and yield compared to the purebred Simmental cows of the same diplotype. The Holstein × Simmental cows with the diplotype AR/AR were also characterised by significantly lower content of C16:0 and saturated fatty acids, but higher C18:1n9, monounsaturated fatty acid and monounsaturated fatty acid/saturated fatty acid content compared to the same diplotype of the Simmental cattle. These results indicate that with accurate breeding plans, crossbreeding Holstein cows with Simmental bulls could be directed towards a more desirable fatty acid composition of milk and dairy products.